You've never had the experience of having a somewhat challenging / unusual request result in an agent abruptly dropping the call?

They can figure out pretty quickly that A) it's going to be hard to help you, and B) you're going to suck a lot of their time, and C) their poor luck of getting your call is going to make them look worse to their management.

I had a sequence of this happening three times with a utility. Unfortunately, it's the fourth agent who actually helped me that got yelled at, at no fault of her own. But I was pretty pissed at that point.